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Geochemistry & Isotope Biogeochemistry Group

Areal distribution of microbial sulfate reduction rates in summer
Sulfate reduction rates in coastal surface sediments during summer time (Al-Raei et al., 2009)


Breaking News:










December, 2021:

Michael E. Böttcher is appointed as Associate Editor in the Editorial Board of the international journal "Isotopes in Environmental & Health Studies"



September 2018:

In collaboration with Swiss colleagues, the research group discovers for the first time a substantial isotope effect for Ba isotopes and presents a new model for oxygen isotope fractionation in the aquatic hyper-alkaline carbonate-forming environments



European Association of Geochemistry (EAG) supports Stable Isotope Session at EGU 2021 in Vienna


This year, for the ninth time since 2012, the European Association of Geochemistry (EAG) is co-organizing and supporting the session

'Application of Stable Isotopes in Biogeosciences'.


Conveneers are: Michael E. Böttcher (IOW Warnemünde), Kirstin Dähnke (HZG Geesthacht),
Gerd Gleixner (MPI Jena), Nikolaus Gussone (Uni Münster)




Outstanding reviewer PPP

In May 2017, Michael Böttcher was awarded as 'Outstanding Reviewer' for the international scientific journal Paleogeography, Paleoclimatology, Paleoecology.





Erfolg durch Eisernen Vorhang


Auf der diesjährigen internationalen ECSA56 (Coastal Systems in Transition)-Konferenz in Bremen wurde ein Beitrag, den der IOW-Doktorand Marko Lipka aus der AG Geochemie & Isotopen-Biogeochemie vorgestellt hat, mit dem diesjährigen Posterpreis ausgezeichnet. So herausgestellt wurde das Poster mit dem Titel:

„Submarine Groundwater Discharge: A source of P and DIC for the southern Baltic Sea
and the role of an Iron Curtain“

des Autor*innenkollektivs: Lipka, Sültenfuß, Wu, Escher, Schmiedinger, Struck, Dellwig & Böttcher. Darin geht es um die Bedeutung von Grundwasser als Quelle von Phosphat und gelöstem anorganischen Kohlenstoff für die Küstengewässer der Ostsee und die Bedeutung von Eisen-Oxyhydroxid Fällungen an Quellwasser-Austritten für die Phosphat-Retention.





Outstanding reviewer GCA


In November 2016, Michael Böttcher was awarded as 'Outstanding Reviewer' for the international scientific journal Geochimica et Cosmochimca Acta.




Happy Birthday (Bio)Geochemistry!

In January 2016, we are celebrating the 10th anniversary of the Geochemistry & Isotope Biogeochemistry Group at the Leibniz IOW, Germany.



Top of the Isotopes

September, 29th, 2015, University of Heidelberg: Professor Dr. Michael Böttcher, head of the Geochemistry & Isotope-Biogeochemistry Group at IOW, was elected as vice speaker of the German Association of Stable Isotope Research (GASIR) during the annual meeting. The GASIR is an association of scientists coming from diverse disciplines. All in common is the application of different stable isotope systems in research.

More informations under:


Outstanding reviewer EPSL

In June 2015, Michael Böttcher was awarded as 'Outstanding Reviewer' for the international scientific journal Earth & Planetary Science Letters.



                                                         Chemical Geology

Starting on August 1st, 2013, Prof. Dr. Michael Böttcher took the responsibility as (co) Editor-in-Chief of the renowned international scientific journal Chemical Geology. He is responsible for the fields: Biogeochemistry, Stable Isotope Geochemistry, Hydrogeochemistry, Low-Temperature Water-Rock Interactions, Carbon and Sulfur Geochemistry, and Paleoceanography.

More informations under:




The key approach of the main research activities are focuses on the process-oriented investigation (field, experiment, model) of separated and connected biogeochemical element cycles with the use of special analytical approaches as stable isotope (S, O, C, H) and redox-sensitive element partitioning (e.g., S, C, O, P, Fe, Mn, Mo). It is reflected by the main research areas:

• Stable Isotope Geochemistry

• Aquatic Geochemistry
• Sediment Geochemistry
• Environmental Geochemistry

• Experimental Geochemistry

• Mineral authigenesis (carbonates, phosphates, sulfates and sulfides)

• Proxy formation processes and application to paleo-environmental changes

• Redox and trace element biogeochemistry




Current Hot Topics:

•  Submarine Ground Water Discharge

•  Ocean Acidification

•  Phosphorous cycling

•  Mineral Authigenesis

•  Redox gradients


Current study areas:

•  Baltic Sea

•  North Sea

•  Black Sea

•  Mediterranean Sea

•  South China Sea


Analytical methods:

Aqueous solutions:

- ICP-OES (major, minor, and trace elements)

- D/H, 18O/16O, 17O/16O, and 2H and 17O-excess in water (Picarro CRDS)

- Concentrations and 13C/12C in DIC and DOC; 34S/32S in e.g., sulfide, sulfate; 18O/16O in sulfate (gas mass spectrometry with different inlet systems- see 'isotope fascility')

- Spectrophotometry (sulfide, iron, phosphate, sulfate, alkalinity)

- Titration analyzer with autosampler (titration alkalinity, chloride)

- Ion sensitive electrodes, laboratory and field instruments, and microsensor stand (pH, oxygen microprofiling)

- Specific conductivity, temperature

Solid phases:

- Chemical sequential extraction lines (sulfur, metal, and phosphorous species)

- D/H and 18O/16O in mineral hydrate water (Picarro CRDS)

- 13C/12C in carbonates; 34S/32S in e.g., sulfides, sulfates; 18O/16O in carbonates and sulfates
  (gas mass spectrometry with different inlet systems- see 'isotope fascility')


Experimental set-ups:

- Experimental set-ups to follow low-temperature dissolution and precipitation reactions under controlled conditions of temperature and CO2-partial pressure (in particular: carbonates, sulfates, phosphates (sulfides))

- Gas mixing device (CO2 - Ar/N2)




Sampling in the German Wadden Sea.   Reference left: Al-Raei et al. (2009) Seasonal dynamics of microbial sulfate reduction in temperate intertidal surface sediments: controls by temperature and organic matter. Ocean Dynamics 59: 351–370.   doi 10.1007/s10236-009-0186-5

Right: Sampling in a Brazilian lagoon

Running projects

  MSc and BSc projects
          There are always open projects for enthusiastic MSc and BSc students.
          Please contact the group leader for further details.
          Examples for current topics are:
       -  Impact of ground water (SGD) on coastal biogeochemistry
       -  Impact of ocean acidification on the biogeochemistry of coastal seas
       -  The carbonate system of marginal seas
       -  Authigenic minerals as process markers
       -  Biogeochemistry of the coupled sulfur-metal cycles in marginal seas
       -  Formation, transformation and destruction of carbonates (e.g. travertin),
       -  phosphates, sulfates, and sulfides
       -  Experimental geochemistry: Trace element and stable isotope fractionation
       -  Modeling of water-rock interactions
       -  Selected field areas: Baltic Sea, North Sea, Black Sea, Brazil, China
  • Graduate colleg Baltic TRANSCOAST (Water and Material Exchange between a coastal peatland and the Baltic Sea)
    TP Biogeochemistry and Isotope Hydrology
    DFG (2019-2026)
    (Current PhDs: MSc Rhodelyn Saban, MSc Anna-K. Jenner, BSc Denise Otto)
MPA-DAM (Impact of fishery on surface sediment biogeochemistry in the southern Baltic Sea)
Subproject Benthic biogeochemistry and element fluxes
BMBF/DAM (2020-2023)
(Post Doc:) Dr. M. Zeller, Dr. P. Roeser
  • DAAD (Impact of groundwater on northern coastal seas)
    DAAD (2018-2022) Stipend
    (PhD stipend: MSc  Cátia M.E. von Ahn)
  • KISNET (Comparison of methods to investigate Submarine Groundwater Discharge)
    DFG (2020-2023)
  • BlackMan (The role of Mn-driven AOM on sediments of the Black Sea Biogeochemistry)
    Stipend (2019-2020)
    Dr. Tiantian Sun
    • COOLSTYLE (Biogeochemistry of Carbon storage in the North - Baltic Sea continuum (part of CARBOSTORE))
      BMBF (2021-2024)
      MSc Càtia M. Ehlert von Ahn (PostDoc), BSc Antonia Schell
Group leader
Group members
Dr. Olaf Dellwig (Senior Scientist)
Iris Schmiedinger (Technical Assistant)
Anne Köhler (Technical Assistant)
Dr. Carla Nantke (PostDoc): Carbon and alkalinity cycle of North and Baltic Sea
Dr. Jurjen Rooze (Guest-PostDoc): Role of bottom trawling on benthic biogeochemistry and modelling
MSc Anna-Kathrina Jenner (PhD student): Flooding of coastal peatlands and submarine groundwater discharge
MSc Rhodelyn Saban (PhD student): Biogeochemistry of coastal systems under impact of of water exchange
MSc Cátia M.E. von Ahn (PhD student): Submarine groundwater discharge in the Baltic Sea
BSc Antonia Schell (MSc student): The role of tidal basins for the carbon cycle in the North Sea
BSc Svante  Peters (MSc student): The carbon system impact of sinter formation on Rügen island
Tamina Bruhnke (BSc student): Mineral formation associated with carbonate sinter formation


Physico-chemical measurements at a carbonate spring on Rügen Island (Foto: F. Tauber)